In the art of integrated circuit structures, in general, a reduction in the footprint of a given circuit is generally considered to represent an improvement in the circuit. In some circumstances, a reduced footprint for the given circuit is achieved by using the same functional components albeit reduced in size and (possibly) altered in shape. Hence, irrespective of the particular nature of a given circuit, a seemingly perennial design goal vis-à-vis the given circuit is to reduce its footprint.
In the art of manufacturing, there is the concept of tolerance. For a given dimension of a structure in an integrated circuit, manufacturing tolerance should be understood as a permissible amount of deviation manifested by an instance of the structure relative to a specified value for the given dimension. Occasionally, the goal of reducing footprint size is frustrated by the realities of manufacturing tolerances.